﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Configuration;

namespace Utility
{
    public class AppConf 
    {

        private static bool cfgFileIsSet = false;

        private static Configuration AppConfig;
        
        public static void SetConfigFile(string FileName)
        {
            AppConfig = ConfigurationManager.OpenExeConfiguration(FileName);
            cfgFileIsSet = true;
        }

        public static void SetDefaultConfigFile()
        {
            AppConfig = null;
            cfgFileIsSet = false;
        }
        
        ///<summary> 
        ///依据连接串名字connectionName返回数据连接字符串  
        ///</summary> 
        ///<param name="connectionName"></param> 
        ///<returns></returns> 
        public static string GetConnectionStringsConfig(string connectionName)
        {
            if (cfgFileIsSet)
            {
                string connectionString =
                    AppConfig.ConnectionStrings.ConnectionStrings[connectionName].ConnectionString.ToString();
                return connectionString;
            }
            else
            {
                string connectionString =
                        ConfigurationManager.ConnectionStrings[connectionName].ConnectionString.ToString();
                //Console.WriteLine(connectionString);
                return connectionString;
            }
        }

        ///<summary> 
        ///更新连接字符串  
        ///</summary> 
        ///<param name="newName">连接字符串名称</param> 
        ///<param name="newConString">连接字符串内容</param> 
        ///<param name="newProviderName">数据提供程序名称</param> 
        public static void UpdateConnectionStringsConfig(string newName,
            string newConString,
            string newProviderName)
        {
            if (cfgFileIsSet)
            {
                bool isModified = false;    //记录该连接串是否已经存在  
                //如果要更改的连接串已经存在  
                if (AppConfig.ConnectionStrings.ConnectionStrings[newName] != null)
                {
                    isModified = true;
                }
                //新建一个连接字符串实例  
                ConnectionStringSettings mySettings =
                    new ConnectionStringSettings(newName, newConString, newProviderName);
                // 打开可执行的配置文件*.exe.config  
                //Configuration config =
                //    ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
                // 如果连接串已存在，首先删除它  
                if (isModified)
                {
                    AppConfig.ConnectionStrings.ConnectionStrings.Remove(newName);
                }
                // 将新的连接串添加到配置文件中.  
                AppConfig.ConnectionStrings.ConnectionStrings.Add(mySettings);
                // 保存对配置文件所作的更改  
                AppConfig.Save(ConfigurationSaveMode.Modified);
                // 强制重新载入配置文件的ConnectionStrings配置节  
                ConfigurationManager.RefreshSection("ConnectionStrings");
            }
            else
            {
                bool isModified = false;    //记录该连接串是否已经存在  
                //如果要更改的连接串已经存在  
                if (ConfigurationManager.ConnectionStrings[newName] != null)
                {
                    isModified = true;
                }
                //新建一个连接字符串实例  
                ConnectionStringSettings mySettings =
                    new ConnectionStringSettings(newName, newConString, newProviderName);
                // 打开可执行的配置文件*.exe.config  
                Configuration config =
                    ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
                // 如果连接串已存在，首先删除它  
                if (isModified)
                {
                    config.ConnectionStrings.ConnectionStrings.Remove(newName);
                }
                // 将新的连接串添加到配置文件中.  
                config.ConnectionStrings.ConnectionStrings.Add(mySettings);
                // 保存对配置文件所作的更改  
                config.Save(ConfigurationSaveMode.Modified);
                // 强制重新载入配置文件的ConnectionStrings配置节  
                ConfigurationManager.RefreshSection("ConnectionStrings");
            }
        }

        ///<summary> 
        ///返回＊.exe.config文件中appSettings配置节的value项  
        ///</summary> 
        ///<param name="strKey"></param> 
        ///<returns></returns> 
        public static string GetAppConfig(string strKey, string DefaultValue = "")
        {
            if (cfgFileIsSet)
            {
                foreach (string key in AppConfig.AppSettings.Settings.AllKeys)
                {
                    if (key == strKey)
                    {
                        return AppConfig.AppSettings.Settings[key].Value.ToString();
                    }
                }
                return DefaultValue;
            }
            else
            {
                foreach (string key in ConfigurationManager.AppSettings.AllKeys)
                {
                    if (key == strKey)
                    {
                        return ConfigurationManager.AppSettings[strKey];
                    }
                }
                return DefaultValue;
            }
        }

        ///<summary>  
        ///在＊.exe.config文件中appSettings配置节增加一对键、值对  
        ///</summary>  
        ///<param name="newKey"></param>  
        ///<param name="newValue"></param>  
        public static void UpdateAppConfig(string newKey, string newValue)
        {
            if (cfgFileIsSet)
            {
                bool isModified = false;
                foreach (string key in AppConfig.AppSettings.Settings.AllKeys)
                {
                    if (key == newKey)
                    {
                        isModified = true;
                    }
                }

                // Open App.Config of executable  
                //Configuration config =
                //    ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
                // You need to remove the old settings object before you can replace it  
                if (isModified)
                {
                    AppConfig.AppSettings.Settings.Remove(newKey);
                }
                // Add an Application Setting.  
                AppConfig.AppSettings.Settings.Add(newKey, newValue);
                // Save the changes in App.config file.  
                AppConfig.Save(ConfigurationSaveMode.Modified);
                // Force a reload of a changed section.  
                ConfigurationManager.RefreshSection("appSettings");
            }
            else
            {
                bool isModified = false;
                foreach (string key in ConfigurationManager.AppSettings)
                {
                    if (key == newKey)
                    {
                        isModified = true;
                    }
                }

                // Open App.Config of executable  
                Configuration config =
                    ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
                // You need to remove the old settings object before you can replace it  
                if (isModified)
                {
                    config.AppSettings.Settings.Remove(newKey);
                }
                // Add an Application Setting.  
                config.AppSettings.Settings.Add(newKey, newValue);
                // Save the changes in App.config file.  
                config.Save(ConfigurationSaveMode.Modified);
                // Force a reload of a changed section.  
                ConfigurationManager.RefreshSection("appSettings");
            }
        } 
    }
}
